Quote:I started using Gimp a few days ago and I don't even know other similar software.
which means you do not have any concepts like layers, mask and so on (see at the bottom),
With GIMP you can do it in less than 5 minutes, but let's face it, I don't want to spend an hour or two writing a tutorial with tens of screenshots pointing what to do.
I'll just give you some youtube tutorial (quickly found), and after watching them you should be able to do what you need.
Anyway after what said Ofnuts (which is a good start)
Quote:- apply an effect (in this case watercolour) towards the margins of the photo, for an amplitude to be evaluated;
- possibly this watercolor effect must already exist, in the sense that a texture should be used (or maybe some other kind of solution that I don't know about), and the edges of this texture
Select the layers you want to apply the watercolor effect, then go to Filters > Artistic > Waterpixel...`
https://www.youtube.com/watch?v=q7W-9xJ533Y
Quote:must be jagged and perhaps with a splash effect, so there could be separate dots and spots;
Splash effect: open the brush dialog and chose the one you like, then "paint on a new layer"
https://www.youtube.com/watch?v=RNjyw5PAVBQ
Quote:- the original edges of the photo must be transformed into the jagged edges of the watercolor effect;
Jagged edges:
https://www.youtube.com/watch?v=rVkOX2eojjY
Quote:- the watercolor effect must not erase the affected parts of the photo but must only modify the image in this way.
Diminish the opacity of that layer until you're happy (look on top of the layer dialog for the Opacity slider)
In all cases... You need to learn a lot...
layer concept:
https://docs.gimp.org/en/gimp-concepts-layer-modes.html (at the bottom right follow the arrow for the next layer modes)
https://docs.gimp.org/en/gimp-concepts-l...egacy.html
Layer Mask
https://www.gimp.org/tutorials/Layer_Masks/